Engine starting system with combination air relay and check valve

ABSTRACT

A valve assembly for use preferably with an engine starting system, the valve assembly including a housing providing a fluid flow path therethrough. A valve seat astride the flow path is disposed in the housing, and a valve head is mounted on a piston reciprocally mounted in the housing. The piston defines, with the housing, a control chamber and a reaction chamber, the latter of which communicates with the flow path downstream of the valve seat. Spring means biases the piston and valve head toward the valve seat so that the flow path is normally closed to fluid flowage therealong. Increased fluid pressure in the control chamber acts on the piston to open valve and thus the flow path, and comparatively high pressure downstream of the valve seat raises the pressure in the reaction chamber to force the valve head against the valve seat to prevent upstream flowage of the gases creating the high downstream pressure.

United States Patent [l5] 3,675,417 [45]- July 11, 1972 Shum, Jr.

[54] ENGINE STARTING SYSTEM WITH COMBINATION AIR RELAY AND CHECK VALVE[72] Inventor John ShurnJn, Valley Station, Ky.

[73] Assignee: Olin Corporation [22] Filed April 15,1971

[2!] Appl. No.: 134,286

[52] US. Cl. ..60/39.l4,60/26.l, l23/l83 [$1] Fine 7/26 [56] ReferenceCited UNITED STATES PATENTS 3,459J65 8/[969 Bender et al ..60/26.l

3.633360 l/l972 Kelley ..60/39. l4

2.559.006 7/195l Clapham... .....60/39.l4

2,154,572 4/1939 Lansing ..60/39. 14

3,087,305 4/l963 Hertz ....60l39.l4

3,l33,4l5 5ll964 Deverell et al ..60/39.l4

f @III. J

Primary xandnerCarlton R. Croyle Assistant Examiner-Warren OlsenAttorney-Donald R. Motslto, H. Samuel Kieser and William W. Jones [57]ABSTRACT downstreamofthevalveaeatraisesthepreesure in Lhereac tionchamber to force the valve head against the valve seat to preventupstream flowage of the gases creating the high downstream pressure.

PATENTEflJuL 1 1 m2 SHEET 2 OF 2 JOHN SHUM JR.

I NV E NTO R ENGINE STARTING SYSTEM WITH COMBINATION All! RELAY ANDCHECK VALVE This invention relates to a combination relay and checkvalve for use with a fluid actuated system, in particular an enginestarting system.

The valve of this invention is more particularly adapted for use with afluid actuated engine starting system which includes a vane motor. Thevane motor is preferably of the type having a plurality of vanes mountedon a rotor, the vanes being exposed to a stream of pressurized fluid soas to cause the rotor to rotate. The vane motor is operably connected tothe engine in such a way that rotation of the vane rotor causes thelatter to engage the engine and crank it until the engine becomesself-sustaining.

The eng'ne starting systems with which the valve of this invention isparticularly useful generally include a tank which contains a supply ofpressurized operating fluid which is used to rotate the vane motor orstarting unit. For purposes of economy and adaptability, the connectionsbetween the pressurized fluid tank and the starting unit may be flexibleplastic or rubber tubing. Systems of this type commonly use a relayvalve interposed between the pressurized tank and the starting unit,which valve is normally closed and can be selectively opened to feedpressurized fluid to the starting unit to actuate the latter. The systemmay also include a device which can be operated to fire a propellantcharge to produce a volume of high pressure, high temperature combustiongases which are utilized instead of the pressurized fluid to actuate thestarting unit. Metal tubing which is corrosion and heat resistant mustbe used to feed the combustion gases into the vane motor, and a separatecheck valve must be interposed between the propellant firing device andthe relay valve to protect the flexible conduits and the pressurizedtank from being exposed to the hot, corrosive combustion gases.

The prior art systems for actuating the vane motor with eitherpressurized operating fluid from a tank, or hot, pressurized combustiongases are undesirably complex in construction and require a number ofseparate valves and subcomponents which must be packaged in a limitedspace. Such systems have proven rather complicated to install andmaintain, and service in the field, rather bulky, and difl'icult tocompletely seal from the elements of weather.

The valve assembly of this invention solves the above-noteddisadvantages found in the prior art by providing a single valve unitwhich is adapted to perform a multiplicity of functions. The valve ishoused in a single housing which is sealed from the surroundingenvironment to protect the various members in the unit from weather andother external harmful influences. The housing includes an inlet portand an outlet port which combine with a portion of the interior of thehousing to define a flow path along which pressurized fluid is fed froma pressure chamber to the starting motor. A valve head and cooperatingvalve seat are positioned within the housing and are selectivelyoperable to control the flow ot' the pressurized fluid to the startingmotor. The valve head is normally biased into engagement with the valveseat so that the valve is normally closed to block the flow ofpressurized fluid through the housing. A piston is preferably mounted inthe housing and is connected to the valve head and movable therewith.The piston provides with the housing a control chamber into whichpressurized control fluid is fed, the pressurized control fluid servingto move the piston within the housing. The piston and valve head arearranged so that an increase in pressure within the control chamberresults in movement of the piston operative to move the valve head awayfrom the valve seat to open the flow path for flowage of operating fluidfrom the pressurized tank to the starting motor.

The piston and housing also cooperate to provide a reaction chamberwhich is disposed upstream of the valve seat. A conduit, preferably inthe form of an aperture drilled through the piston, provides fluidcommunication between the reaction chamber and the portion of the flowpath downstream of the valve seat. A check valve is preferably disposedso as to normally close the conduit to fluid flow, the check valve beingar rangedsoastoopenwhenfluidpressureintheoutletor downstream portion ofthe flow path substantially exceeds fluid prenure in the inlet orupstream portion of the flow path. The latter condition will typicallyoccur when the propellant firing device is used to actuate the startingmotor. When the check valve opens in response to high fluid pressuredownstreamofthevalvehesdandseat, the pressurein the reaction chamberincreases so as to force the piston and valve head toward the valveseat. Thus the high pressure gases acting on the piston dowmtream of thevalve and tending to open the valve, are counteracted and the valveremains closed. In this manner high pressure combustion gases cannotforce the valve to open and the combustion gases are thus not free topass upstream into the flexible conduits and preuurized tank to damagethe latter.

It is therefore, an object of this invention to provide a valve assemblyfor use with a fluid flow system wherein the valve assembly functionsboth as a fluid relay valve and a reverse flow check valve.

It is yet another object of this invention to provide a valve assemblyof the character described wherein actuation thereof as a relay valve isachieved by means of a varying a control fluid pressure.

It is still a further object of this invention to provide a valve of thecharacter described wherein actuation thereof as a check valve isachieved by means of a reaction chamber in fluid communication with thedownstream portion of the fluid flow path.

It is an additional object of this invention to provide a valve assemblyof the character described which is contained in a single housing forassembly and maintenance.

It is still another object of this invention to provide a fluid actuatedengine starting system incorporating a single valve assembly operativeto regulate flow of the operating fluid and prevent backward flow ofhigh presure, hot combustion gases.

These and other objects and advantages oi the invention will become morereadily apparent from the following detailed description of a preferredembodiment of the invention, and the accompanying drawings, in which:

FIG. I is a schematic diagram of an engine starting system incorporatingthe valve assembly of this invention;

FIG. 2 is a cross-sectional view of the housing of FIG. 1 showing thevalve in its closed position with the reaction chamber being closedagainst fluid communication with the downstream portion of the flowpath;

FIG. 3 is a sectional view similar to FIG. 2 but showing the valve inits open position to permit operating fluid flow through the housing;and

FIG. 4 is a sectional view similar to FIG. 2 but showing the reactionchamber open to fluid flowage from the downstream portion of the flowpath whereby the valve is closed by high preuure in the reactionchamber.

Referring now to FIG. 1 an engine starting system is shownschematically. The system includes a tank 2 in which is storedpressurized operating fluid which can be used to rotate the vanes in aconventional vane-type starting motor 4. A line 3 is connected to acompressor (not shown) to maintain the fluid pressure in the tank 2. Thestarting motor 4 includes a gear 6 which is mounted on a roatable shaft(not shown) and which, when actuated, is moved axially into engagementwith a complimentary gear 8 which is mounted on a shaft 10. Rotation ofthe shaft 10 turns the engine 12 over to crank the latter. The startingmotor and the manner in which it operates to crank the engine areconventional and form no independent part of this invention. A flexiblerubber or plastic conduit 14 is connected to the presurized operatingfluid tank 2 and extends therefrom to a valve housing 16.

A propellant charge firing device 18 of conventional construction ispositioned downstream of the operating fluid tank 2 and is connected toa metal conduit 20 adapted to conduct high pressure, high temperaturecombustion gases generated when a charge of propellant is fired in thedevice 18. The conduit is connected to s similar metal conduit 22 whichextends between the housing 16 and the starting motor 4. It is thusapparent that either the pressurized operating fluid from the tank 2 orcombustion gases from the device 18 may be used to actuate the startingmotor 4. A tank 24 containing a supply of pressurized operating fluid isconnected to a flexible conduit 26 which leads to the housing 16. Avalve 28 regulates flow of the control fluid from the tank 24 throughthe line 26. A remote actuator 30 is connected to the valve 28 so thatthe latter can be operated from some remote point, such as in the cab ofthe piece of apparatus which the engine 12 runs.

Referring now to FIG. 2, the housing 16 is shown in crosssection. Thehousing 16 includes an inlet port 32, to which is connected the flexibleconduit 14, and an outlet port 34, to which is connected the metalconduit 22. A valve seat 36 is disposed in the housing between the inlet32 and outlet 34. the valve seat 36 defining an orifice whichinterconnects the inlet 32 and outlet 34 to permit fluid flow betweenthe two. A piston indicated generally by the numeral 38 is reciprocallymounted in the housing 16. The piston 38 includes a first enlarged headportion 40 having an exterior groove 42 in which is mounted a resilientring 44 which engages the side wall 46 of a portion of the housing andwhich forms a fluid-tight seal therewith. The piston head 40 and thehousing wall portion 46 combine to form a chamber 48. A port 50 opensinto the chamber 38, the port 50 being connected to the flexible conduit26 which extends from the control fluid tank 24. Thus the chamber 48will be referred to as the control chamber since the pressurized controlfluid is directed thereinto.

The piston 38 also includes a second enlarged head portion 52 having anexternal groove 54 in which is seated a resilient ring 56. A plug member58 is screwed into the housing 16, the plug member 58 having an internalcylindrical bore 60 in which the piston head 52 is disposed. Theresilient ring 56 forms a fluid-tight seal with the wall of the bore 60and the piston head 52 defines a second chamber 62 with the wall of thebore 60. The chamber 62 is termed the reaction chamber for reasons setforth more explicit hereinafter.

A flange 64 is formed on the piston 38, the flange 64 having a groove 66in which is seated a resilient valve head member 68. A spring 70 ismounted in the reaction chamber 62 the spring 70 engaging the piston 38to bias the latter so that the valve head 68 is urged into sealingengagement with the valve seat 36. Thus the valve is normally closed toprevent fluid flow from the inlet 32 to the outlet 34. A hole 72 isdrilled through the piston 38 downstream from the valve seat 36, thehole 72 providing fluid communication between the outlet port 34 and thereaction chamber 62. A valve head 74 of nylon or other suitable materialis movably mounted in the reaction chamber. A spring 76 is mounted inthe reaction chamber 62 in engagement with the valve head 74 to bias thelatter into sealing engagement with an annular valve seat 78 interposedbetween the hole 72 and the reaction chamber 62. Thus a check valvearrangement is provided to normally close the reaction chamber 62 fromthe outlet port 34.

The valve assembly operates in the following manner. When the operatordesires to actuate the starting motor 4 by means of operating fluid fromthe tank 2, he uses the actuator 30 to open the valve 28 to permitpressurized control fluid to flow from the tank 24 into the controlchamber 48. Thus the fluid pressure in the control chamber 48 isincreased to cause the piston 38 to move against the bias of the spring70 to compress the latter. The valve head 68 is thereby moved away fromthe valve seat 36 to open the valve thus permitting operating fluid toflow from the tank 2 through the inlet port 32 and to the outlet port 34along a path indicated generally by the arrows 80 in FIG. 3. It is notedthat the check valve in the reaction chamber 62 remains closed when themain valve is thus opened.

ll the operator desires to actuate the starter motor 4 by firing apropellant charge with the device 18, the latter is loaded with thecharge and fired to create a volume of high pressure, high temperaturecombustion gases. The gases travel through so that the high pressuregases thus flow into the reaction chamber 62 to act upon the rear faceof the piston head 52. Thus the action of the cornbustion gases on thedownstream side of the flange 64 is countered by the opposite reactionof the combustion gases on the piston head 52 so that the spring is ableto keep the valve head 68 seated against the valve seat 36. Therefore,the valve will not open when the pressure in the outlet port 34 issubstantially greater than pressure in the inlet port 32 so that thecombustion gases are prevented from flowing upstream past the housing 16and into the operating fluid tank 2.

It is readily apparent that the valve assembly of this invention iscontained in a single housing thus facilitating ease of assembly andfield maintenance. The valve provides dual capabilities of operatingfluid relay and rearward checking of combustion gases when used in adual actuated engine starting system.

Since many changes and variations of the disclosed em bodiment of theinvention may be made without departing from the inventive concept, itis not intended to limit the invention otherwise than as required by theappended claims.

What is claimed is:

1. An engine starting system comprising:

a. a source of pressurized operating fluid;

b. a source of pressurized control fluid c. a vane motor;

d. a housing having an inlet and an outlet and providing a fluid flowpath from said inlet to said outlet;

e. first conduit means connecting said operating fluid source to saidhousing inlet;

fv second conduit means connecting said vane motor to said housingoutlet;

g. a propellant firing device;

h. third conduit means connecting said propellant firing device to saidsecond conduit means;

i. a valve seat in said housing astride said flow path;

j. piston means mounted in said housing, said piston means combiningwith a first portion of said housing to provide a control chamber, andsaid piston means combining with a second portion of said housing toprovide a reaction chamber whereby predetermined increased fluidpressure in said reaction chamber is operative to move said piston meansin a first direction, and predetermined fluid pressure in said controlchamber is operative to move said piston means in the oppositedirection;

. a valve head mounted on said piston means, said valve head beingmovable into sealing engagement with said valve seat to close said flowpath when said piston means is moved in said first direction, and saidvalve head being movable away from said valve seat to open said flowpath when said piston means is moved in the opposite direction;

I. fourth conduit means interconnecting said pressurized control fluidsource with said control chamber; and

m. fifth conduit means interconnecting said reaction chamber with apoint on said flow path downstream of said valve seat, whereby increasedfluid pressure created downstream of said valve seat by firing saidpropellant firing device results in increased fluid pressure in saidreaction chamber operative to move said valve head against said valveseat to close said flow path against upstream flow of combustion gases.

2. The engine starting system of claim 1, wherein said fifth conduitmeans extends through said piston means.

3. The engine starting system of claim I, further comprising springmeans contacting said piston means to bias the latter in said firstdirection whereby said flow path is nonnally closed.

4. The engine starting system of claim 1, further oomprining check valvemeans in said fifth conduit means operative to open only when downstreamfluid preaure in said flow path is increased by firing said propellantfiring device.

1. An engine starting system comprising: a. a source of preSsurizedoperating fluid; b. a source of pressurized control fluid c. a vanemotor; d. a housing having an inlet and an outlet and providing a fluidflow path from said inlet to said outlet; e. first conduit meansconnecting said operating fluid source to said housing inlet; f. secondconduit means connecting said vane motor to said housing outlet; g. apropellant firing device; h. third conduit means connecting saidpropellant firing device to said second conduit means; i. a valve seatin said housing astride said flow path; j. piston means mounted in saidhousing, said piston means combining with a first portion of saidhousing to provide a control chamber, and said piston means combiningwith a second portion of said housing to provide a reaction chamberwhereby predetermined increased fluid pressure in said reaction chamberis operative to move said piston means in a first direction, andpredetermined fluid pressure in said control chamber is operative tomove said piston means in the opposite direction; k. a valve headmounted on said piston means, said valve head being movable into sealingengagement with said valve seat to close said flow path when said pistonmeans is moved in said first direction, and said valve head beingmovable away from said valve seat to open said flow path when saidpiston means is moved in the opposite direction; l. fourth conduit meansinterconnecting said pressurized control fluid source with said controlchamber; and m. fifth conduit means interconnecting said reactionchamber with a point on said flow path downstream of said valve seat,whereby increased fluid pressure created downstream of said valve seatby firing said propellant firing device results in increased fluidpressure in said reaction chamber operative to move said valve headagainst said valve seat to close said flow path against upstream flow ofcombustion gases.
 2. The engine starting system of claim 1, wherein saidfifth conduit means extends through said piston means.
 3. The enginestarting system of claim 1, further comprising spring means contactingsaid piston means to bias the latter in said first direction wherebysaid flow path is normally closed.
 4. The engine starting system ofclaim 1, further comprising check valve means in said fifth conduitmeans operative to open only when downstream fluid pressure in said flowpath is increased by firing said propellant firing device.